/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup LibIOFSOps File System Operations
*
* @brief RTEMS Default File System reposits the offset of the open file fd
*/
/*
* Copyright (c) 2012 embedded brains GmbH & Co. KG
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/libio_.h>
off_t rtems_filesystem_default_lseek_file(
rtems_libio_t *iop,
off_t offset,
int whence
)
{
off_t rv = 0;
off_t reference_offset;
struct stat st;
switch ( whence ) {
case SEEK_SET:
reference_offset = 0;
break;
case SEEK_CUR:
reference_offset = iop->offset;
break;
case SEEK_END:
st.st_size = 0;
rv = (*iop->pathinfo.handlers->fstat_h)( &iop->pathinfo, &st );
reference_offset = st.st_size;
break;
default:
errno = EINVAL;
rv = -1;
break;
}
if ( rv == 0 ) {
off_t new_offset = reference_offset + offset;
if (
(offset >= 0 && new_offset >= reference_offset)
|| (offset < 0 && new_offset < reference_offset)
) {
if ( new_offset >= 0 ) {
iop->offset = new_offset;
rv = new_offset;
} else {
errno = EINVAL;
rv = -1;
}
} else {
errno = EOVERFLOW;
rv = -1;
}
}
return rv;
}
